Chemistry Flashcards
Define matter
Anything that takes up space and has mass
Define atom
The smallest unit of matter that retains the property of the element and can be broken into 3 subatomic particles (neutron, proton, electron)
T or F: an uncharged atom has a neutral charge
True because the electron and proton cancel each other out
What are the 3 subatomic particles that make up an atom?
- electron
- neutron
- proton
Define potential energy
the energy that matter has because of its location or structure
ex. objects at the top of a hill have more potential energy than those at the bottom
define an electron shell
electrons have different energy levels and each shell is representative of an electron’s state of potential energy
the further away an electron is from the nucleus, the higher energy it has
Define compound
A substance consisting of 2+ elements in a fixed ratio
Define atomic number
Each atom has a unique number that identifies how many protons it has
ex. hydrogen has one proton so it has atomic number 1
Define atomic mass
the approximate weight of an atom measured by taking the sum of protons and neutrons
How is the behaviour of an atom determined?
By the distribution of electrons in their electron shells
Define valence electrons
the electrons in the outermost shell (valence shell)
Define metals and give an example
Elements with high electrical conductivity, lustre (shine), and malleability
Readily lose electrons to form positive ions (cations)
ex. H, Li, Mg, Ca, Mn, etc.
Define non-metals and give an example
elements that are poor electrical conductors, lack lustre, are brittle and tend to gain electrons to form negative ions (anions)
ex. B, C, N, O, F, etc.
Define electron orbital
A 3D space where an electron is found 90% of the time
Each shell consist of a specific number of orbitals
Define chemical bonds
an interaction between two atoms
Define covalent bonds
An interaction between two atoms in which they share electrons in their valence shells (ie electrons orbit around both atoms)
Define molecule
Two or more atoms held together by covalent bonds
Define electronegativity
An atom’s strength of attraction for electrons
If an atom is more electronegative, it will have more or less ability to pull electrons from less electronegative atoms?
MORE
Define polar covalent bonds
Interactions between two atoms in which they are NOT sharing electrons equally. Resulting in partial charges for atoms or molecules
Give an example of a polar covalent bond
N-H
O-H
O-C
Define non-polar covalent bonds
Interactions between two atoms in which they share electrons because they have the same/similar electronegativity
ex. C-H
Define ionic bonds
A weak interaction between two atoms with a large difference in electronegativity so they do not equally share electrons and one atom will strip an electron from the other to form ions.
usually between a metal and non-metal
T or F: ionic bonds are always strong
FALSE.
Ionic bonds are weak in water due to the partial charges of water but are very strong in dry environments
